ProjectNatureChange.java

package bndtools.refactor;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectDescription;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;

public abstract class ProjectNatureChange extends Change {

    protected final IProject project;

    public ProjectNatureChange(IProject project) {
        this.project = project;
    }

    @Override
    public void initializeValidationData(IProgressMonitor pm) {
        // TODO
    }

    @Override
    public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException, OperationCanceledException {
        RefactoringStatus status = new RefactoringStatus();
        // TODO
        return status;
    }

    @Override
    public final Change perform(IProgressMonitor pm) throws CoreException {
        final IProjectDescription desc = project.getDescription();
        Set<String> natures = new HashSet<String>(Arrays.asList(desc.getNatureIds()));
        boolean changed = modifyNatures(natures);
        if (changed) {
            desc.setNatureIds(natures.toArray(new String[0]));
            project.setDescription(desc, pm);
        }

        return createInverse();
    }

    protected abstract boolean modifyNatures(Set<String> natures);

    protected abstract Change createInverse();

    @Override
    public Object getModifiedElement() {
        return project;
    }

}